dbztool is a command-line tool for manipulating the bootstrap interface of a Dragonball VZ processor. It will allow you to upload and download data, run programs, examine and modify the system registers, etc. Currently it's only been tested on the Alphasmart Dana but it should work on other machines too (although a number of places in the code assume you're using UART1, which need to be fixed).
Check out the GitHub repository and build from source.
Dependencies are minimal, but you'll need
xxd and the gcc M68K toolchain. You
should just be able to edit the Makefile and then run
make and get a binary
The online help should be reasonably up to date, but as an example:
dbztool -p /dev/ttyUSB0 dump 0xfffffe00 512
However, everything's in flux, so that's basically all there is...
dbztool is open source software available under the 2-clause BSD license. Simplified summary: do what you like with it, just don't claim you wrote it.